Debt - January 2012, May 2014, and November 2015 Exchangeable Senior Notes - Additional Information (Detail)		1 Months Ended				3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2017 USD ($)	Aug. 31, 2016 USD ($) shares	Nov. 30, 2015 USD ($)	May 31, 2014 USD ($)	Jan. 31, 2012 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) shares
Debt Disclosure [Line Items]
Proceeds from issuance of convertible debt, net of transaction costs								$ 30,000,000
Convertible senior notes, repayment								15,107,000
Convertible senior notes, carrying value, exchanged										$ 127,300,000
Gain on change in fair value of derivative liabilities							$ 5,810,000		$ 4,560,000
Interest								$ 7,546,000	7,668,000
Convertible Debt
Debt Disclosure [Line Items]
Convertible senior notes, stated interest rate								3.50%
Convertible senior notes, principal amount										150,000,000
Convertible notes, interest expense									6,900,000
Accrued interest on convertible note								$ 0		200,000
Interest								300,000	2,500,000
Convertible Debt | Non Cash
Debt Disclosure [Line Items]
Convertible notes, interest expense									4,000,000
Convertible Debt | Cash
Debt Disclosure [Line Items]
Convertible notes, interest expense								100,000	2,900,000
Convertible Debt | Common Shares
Debt Disclosure [Line Items]
Carrying amount of debt conversion option										$ 40,100,000
Convertible Debt | American Depositary Shares
Debt Disclosure [Line Items]
Convertible senior notes, total ADS into which the debt is exchangeable | shares										60,311,188
Transaction costs										$ 700,000
Convertible Debt | 2012 Notes
Debt Disclosure [Line Items]
Convertible senior notes, principal amount			$ 15,100,000	$ 31,300,000	$ 150,000,000			0		15,100,000
Convertible senior notes, stated interest rate	3.50%				3.50%
Convertible senior notes, due date	2032				2032
Proceeds from issuance of convertible debt, net of transaction costs					$ 144,300,000
Convertible senior notes, principal amount purchase	$ 15,000,000		16,200,000			$ 15,000,000
Convertible senior notes, repurchase price at option of the issuer	100.00%				100.00%
Convertible senior notes, aggregate principal amount redeemed						$ 100,000		100,000
Convertible senior notes, outstanding amount								$ 0
Carrying amount of debt conversion option					$ 23,800,000
Decrease to additional paid-in capital for repurchase of conversion option in convertible notes				10,100,000
Note, estimated remaining life					24 months			24 months
Convertible senior notes, discount										0
Convertible Debt | 2012 Notes | Other Debt Obligations
Debt Disclosure [Line Items]
Convertible senior notes, fair value					$ 126,200,000
Convertible Debt | 2014 Notes
Debt Disclosure [Line Items]
Convertible senior notes, principal amount		$ 118,700,000		$ 118,700,000				$ 0		0
Convertible senior notes, stated interest rate				3.50%
Convertible senior notes, due date				2032
Convertible senior notes, principal amount				$ 118,700,000
Convertible senior notes, repurchase price at option of the issuer				100.00%
Convertible senior notes, fair value				$ 90,800,000
Decrease to additional paid-in capital for repurchase of conversion option in convertible notes			1,300,000
Convertible senior notes, discount				27,900,000
Offering costs				2,500,000
Derivative liability at fair value				$ 3,500,000
Gain on change in fair value of derivative liabilities									1,500,000
Convertible Debt | 2014 Notes | Final As-Adjusted | American Depositary Shares
Debt Disclosure [Line Items]
Convertible senior notes, exchange rate of ADS per $1,000 principal amount of notes		402.0746
Convertible senior notes, total ADS into which the debt is exchangeable | shares		47,739,925
Convertible Debt | 2015 Notes
Debt Disclosure [Line Items]
Convertible senior notes, principal amount		$ 31,300,000	$ 31,300,000					0		0
Convertible senior notes, stated interest rate			3.50%
Convertible senior notes, due date			2032
Proceeds from issuance of convertible debt, net of transaction costs			$ 27,500,000
Convertible senior notes, repayment			$ 15,900,000
Equity component of convertible notes issuance cost										87,400,000
Debt instrument increase accrued interest										800,000
Convertible senior notes, repurchase price at option of the issuer			100.00%
Convertible senior notes, fair value			$ 27,500,000
Carrying amount of debt conversion option								$ 11,500,000		$ 11,500,000
Convertible senior notes, discount			3,800,000
Offering costs			100,000
Derivative liability at fair value			$ 500,000
Gain on change in fair value of derivative liabilities									$ 400,000
Convertible Debt | 2015 Notes | Final As-Adjusted | American Depositary Shares
Debt Disclosure [Line Items]
Convertible senior notes, exchange rate of ADS per $1,000 principal amount of notes		402.0746
Convertible senior notes, total ADS into which the debt is exchangeable | shares		12,571,263